λ-Eye: a high-sensitivity γ imaging probe for axillary sentinel lymph node mapping

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Surgical Guidance

Background:

• Sentinel lymph node mapping is crucial for cancer staging and treatment planning.
• Existing gamma imaging probes may lack the optimal sensitivity or spatial resolution for certain applications.
• Previous theoretical models and simulations guided the design of an improved probe.

Purpose of the Study:

• To construct and evaluate the performance of the 'λ-eye' gamma imaging probe.
• To optimize the probe for enhanced sensitivity in sentinel lymph node mapping.
• To experimentally validate simulation results and assess the probe's capabilities in small animal models.

Main Methods:

• Construction of the 'λ-eye' gamma imaging probe.
• Performance evaluation using phantoms to measure spatial resolution, energy resolution, sensitivity, and uniformity.
• Proof-of-concept lymph node imaging in normal mice.

Main Results:

• The probe demonstrated an energy resolution of 36±2% and spatial resolution of 2.2 mm at a 2 mm source-collimator distance.
• Integral and differential uniformity values were measured within the useful and central fields-of-view.
• Clear imaging of mouse lymph nodes was achieved with a 10-second acquisition time.

Conclusions:

• The 'λ-eye' probe combines high sensitivity (∼1.5 counts/s/kBq) with good spatial resolution for sentinel lymph node mapping.
• Its compact size (40mm×40mm×70mm) facilitates intraoperative use and detailed scanning.
• The probe's performance validates its potential for improved surgical guidance and diagnostic imaging.